1. Field of the Invention
The present invention relates to an ultraviolet imaging system for use in an ultraviolet imaging apparatus, etc., and in particular, relates to an ultraviolet imaging system (photographing system) in which distortion is adequately corrected.
2. Description of the Prior Art
As an example of a conventional ultraviolet imaging system, a wide-angle lens system disclosed in Japanese Patent No.2858639 and Japanese Patent No.3042766 have been known; and a converging lens system disclosed in Japanese Unexamined Patent Publication No.Hei-10-104510 has been known. Note that a converging lens system generally has a narrower angle-of-view, and is used in a narrow-wavelength-band.
The above-mentioned wide-angle lens system can attain a desirable imaging quality in a typical photographing operation; however, the correcting of distortion is not sufficiently made therein. Accordingly, a wide-angle lens system is not appropriate for photography in which a distorted image should be eliminated.
The above-mentioned converging lens system generally has an angle-of-view of about 2 degrees, i.e., the photographing field is too narrow. Accordingly, a converging lens system is not suitable for an imaging system (photographing system) to be mainly used to photograph an object at a closer distance.